In the deep, bioluminescent bacteria bloom bright

Imagine swimming to the bottom of the sea, the water growing impossibly deep and dark the farther you travel. At these depths, beyond the reach of the sun, live strange new sources of light. Fish, jellyfish, and even bacteria light up these midnight waters.

According to new research in PLOS ONE, the light of this deep-sea bioluminescence waxes and wanes with seasonal changes on earth’s surface. In the Mediterranean winter, cold winds cause surface water to cool. As the surface cools, it becomes denser than the water beneath it, and begins to sink. Convection can also cause this layer to expand, potentially extending it to the Mediterranean Sea’s basin floor. When these phenomena occur side by side, as they can in the northwestern part of the Mediterranean Sea, carbon matter from the surface circulates into deeper waters. Think of it as Nature’s way of stirring the pot.